The proposed study will examine the enzymatic mechanisms of triglyceride removal from plasma lipoproteins in man and swine. The major objectives are: 1) production of antisera to purified triglyceride lipases from post-heparin plasma, liver and adipose tissue; 2) development of a radioimmunoassay for the enzymes using these antisera; 3) evaluation of enzyme mass and activity under conditions which will allow determination of activating and inhibitory effects of apolipoproteins on other substances in plasma and tissue; 4) organ, cellular and subcellular localization of the enzymes by electron microscopy of ferritin or peroxidase labeled antibodies; 5) attempt to show interaction of the lipoproteins with the tissue enzyme sites by these immunohistologic techniques.